1. Technical Field
Aspects of the invention relate to an image reading device used for imaging apparatuses such as facsimile machines, scanners, and copiers.
2. Related Art
Image reading devices have been used for imaging apparatuses such as facsimile machines, scanners, copiers, and the like. An example of such an image reading device is illustrated in FIG. 7, which is a central cross-sectional view showing the internal configuration of a facsimile machine 80. In FIG. 7, a two-dot chain line 81 indicates a feeding path of a document 82. An image on the document 82 being fed along the feeding path 81 is read by a CIS (Contact Image Sensor) 84. The CIS 84 is fixed on a lower cover 85, while the document 82 is held between the CIS 84 and a document holder 86 which is placed above the CIS 84. The document holder 86 is supported by an upper cover 88 to be substantially movable in the vertical direction in FIG. 7 and is biased downward by a compression spring 90. A similar structure is disclosed in Japanese Patent Provisional Publication No.2003-125140, in which a white reference board is provided and is urged toward the CIS.
By biasing of the movable document holder 86 or white reference board toward the CIS 84, the document is pressed against the CIS 84, and positioned within the depth of field of the CIS 84.
However, in the above techniques in which the member placed to face the CIS 84 (the document holder 86 in the technique of FIG. 7 or the white reference board in Japanese Patent Provisional Publication No.2003-125140) is required to be movable and urged toward the CIS 84, a space for allowing the movement of the member has to be provided and a mechanism for supporting the member to be movable has to be provided to the upper cover 88, resulting in an increase in the size of the upper cover 88.